Post-hole digger.



E. L. HALLB.

POST HOLE DIGGER.

APPLICATION FILED FBB.3,1912.

Patented Jan. 14, 1913.

.A W a a E. L. HALLE.

POST HOLE DIGGER.

APPLICATION FILED FEB.3,1912.

1,050,361 Patented Jan. 14, 1913.

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E. L. HALLE.

POST HOLE BIGGER.

APPLICATION FILED IEB. s, 1912.

Patented Jan. 14, 1913.

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BUST-HOLE moan Specification of Letters Patent.

Appllcation fllod February 8, 1912. Serial 30.875411.

Patented Jan. 14,1913.

of which the following is a specification.

This invention relates to machines of that type commonly known in theart as post;

hole diggers and one of the principal objeets'bf the invention is theprovision of av simple and efiicient machine of this character whichwill have a relatively great range of adjustment so as to be adaptablefor all classes of work.

While the machine is especially designed for digging or forming holesfor the recep-;

tion of telegraph, telephone, trolley poles, orj the like, alongside ofrailroad tracks where. frequently it is necessary to dig the holes onthetop of steep embankments orat the.-

bottom of fills, it will be understood that it is also adapted for otherpurposes of similarf for operating the worm shaft and rotating the masthas not been shown nor-has .the

nature.

Another object of the invention is the provision of novel cuttinmechanism which obviates the difliculty tered in cutters of this type,namely, the lateral thrust of the cutter chains or buckets which whencontrolled in one direction, frequently were bound in the hole in suchmanner as to stop the rotation thereof.

Another object of the invention is the provision of a novel form ofcutting mechanism which includes a freely movable cut ter mounting framewhich carries the cutters or bucket chains downwardly by gravity, thusfeeding the cutters gradually according to the hardness of the groundand thereby avoiding sticking or jamming as where the cutters are forcedinto the ground.

Further objects of this invention will appear as the following specificdescription is read in connection with the accompanying drawing, whichforms a part of this application, and in which 2- Figure 1 is a sideelevation with the truck and driving mechanism omitted. Fig. 2 is a topplan view of the boom with parts broken away and with the mast insection.

eretofore encoun- Fig. 3 is a sec'tionr-on the line 33 of Fig. 1. Fig. 4is a similar viewon the line 4-4 of Fig. 1. Fig. 5 isan enlarged detail.side elevation .of the :cutter frame .and its assoelated parts. Fig. 6is .an enlarged front elevation of the cutter frame with .pants cutterframe not shown in Fig. 5. F 8 is a horizontal section on the line 8-8of Fig. 6. Fig. 9 is a detail vertical section on the line 99-of Fig. 5.Fig. 10 is a vertical section on the line 10l0 of Fig. 6 and showingonlythe frame. Fig. 11 is a detail side elevation showin 'the manner ofadjusting the bucket -c ains on the frame. Fig. 12 is a sectional viewon the line '12-12 of Fig. 9 showing the bucket frame only.

Referring more particularly to the draw ing, 1 represents a suitablemast which is revolubly mounted in a bearing 2 and carries a worm gear 3operated through a worm 4 on a worm shaftii. The:mechanism and S of theboom a-re pivoted. These members are connected together by clampingplates 10 and slidably mounted between the membersand the clampingplates is a tubular extension :member 11 provided with a yoke head .12at its outer end. The forward clamping plate has an adjusting screw 13passing therethrough which is adapted to omitted and parts in .section.Fi 7 is a detail elevation of the opposite si e of the engage .one of aplurality of holes '14 formed 7 in the boom extension '11. By thismeans, it will be seen that the boom may be ad- ,j-usted as to length byremoving the set screw from the apertures and loosening the clampingplates.

J ournaled in the yoke head 12 is a shaft 15 upon which a double grooverope sheave 16 is secured and operating over this sheave is a drivingrope or cable 17, the lower strand or leg of which passes over a guidingpulley 18 carried by the clamp 6 and extends to the operating mechanism,not shown. The opposite or upper strand or leg of the drivingcable'passes over a pulley 19 which is carried by an adjustable frame 20slidably mounted upon the mast 1.

Secured to the yoke head 12 and surrounding the-shaft 15 are bearingmembers 22 u on which are journaled the uide. rods 23 w use lower endsare connecte by means of the yoke frame 24. Slidably mounted upon theguide bars is a cross head 25 which carries a frame 26 consistin of sideplates 27 and inset end plates 28; he frame also carries a continuousflan e 29, the purpose of which will be hereina ter described.

Journaled in bearings 30 carried b the cross head, and extending throughthe rame is a chain driving shaft 31 hav ng sprocket wheels 32 and 33arranged on-opposite ends thereof to receive the driving chains 34 and34' which extend from s rocket wheels 35 and 35' on a shaft 36 which isjournaled in bearings 37 carried by the guide rods or bars 23, tosprocket wheels 38 mounted upon stub shafts 39 carried by the yoke frame24. In order to hold the chains 34 in engagement with the sprockets 32,suitable stub shafts 40 are journaled in bearings 41 carried by thecross head 25 and carry upon their ends idler sprockets 42 which arearranged upon op osite sides of and, out of alinement with the sprocketwheels 32. Y The shaft 36 is provided upon its outer ends with sprocketwheels 43 and 44, the former being driven by a chain 45 which passesover a sprocket wheel 46 carried on the shaft 15. The sprocket wheel. 44is mounted upon a sleeve 47 which is loosely journaled upon the shaft 36and also carries the sprocket wheel 35. The gear 44 is driven through achain 48 which operates over a sprocket 49 carried by a stub shaft 50which is driven through a gear 51 meshing with a similar gear 52 uponthe stub shaft 50. It will, therefore, be seen that the chains 34 and 34are driven in opposite directions.

The sprocket wheel 33 is carried upon a sleeve 53 which is rotatablymounted 'upon the shaft 31 and carries at its inner end a lower end ofthe frame 26 in similar positions to the sprockets 54 and 55. The shaft58.is secured in bearing blocks 59 which are slidably mounted betweenthe projectng ends of the side plates 27 of the frame and are held inadjusted position by set screws 60 mounted in opposite cars 61 which arestruck up from the end plates of the frame. Pass-- ing over thesprockets 54 and 55 and 56 and 57 are chains 62 and 63 which carryconveyer buckets 64 being reinforced with cutting blades 65 projectingfrom their forward upper edges. -It will readily be seen that theseconveyer chains are operated in opposite direct-ions and in order todump the material therefrom, there is secured to and projecting fromopposite sides of the cross ead suitable chutes 66 and 67 which receivethe dirt from the buckets and discharge it upon opposite sides of thehole formed.

In order to raise the frame 26 after the hole has been dug, there isloosely journaled upon the shaft 15 a pair of grooved pulleys 68 and 69over which there are passed the lifting ropes 70 which are connected tothe yoke 71 secured to the upper ortion of the crosshead. These ropesmay e connected to any suitable type of raising mechanism, not shown.When the frame 26 is elevated so that the bearing 41 on the cross headcontacts with the bearings 37 on the guiding rods 23, the boom will beelevated if the winding mechanism, just mentioned, is further operated.The downward movement of the frame 26 is limited by contact of the lowerbearings on the cross head with the arm 72 which is carried by the yoke24 and to which the guide bars 23 are connected. This yoke also hasprojecting from its lower end similar attaching arms 73 to which thepenetrating members 74 are secured. These members are adapted to enterthe ground upon opposite sides of the hole and to support the weight ofthe boom and its associated mechanism and are also adapted to preventany lateral movement of the parts.

In order to prevent the guide bars 23 from swinging upon the end of theboom while the device is in operation, I provide a brace member 75 whichis connected at its lower end to opposite sides of the yoke 24 and atits upper end is connected to the depending arms 76 of a clamp 77 whichsurrounds the boom and is held in adjusted position thereon by means ofthe bolts 78. The position I of this clamp member upon the boom does nothave to be changed until the level of the ground changes, at which timethe bolts 78 are loosened so as to permit the guiding rods 23 to swingfreely upon the shafts 15. This will permit the guiding rods and frameto automatically assume a vertical position. When the penetratingmembers 74 have entered the ground the bolts 78 may be tightened so asto maintain the angular relation between the guide rods 23 and the boomand thereby prevent swinging of the frame as the same enters the ground.

What I claim as new is 1. In a hole digging apparatus, the combinationwith a boom, of a support depending from the boom, 0. frame freelyslidably mounted upon the support, a plurality of cutting elementscarrie by the frame and comprisin continuous bucket elevators, and meansto rive one of the elevators in an opposite direction to the others.

2. In a hole di ging apparatus, the combination with a cm, and a supportdepending from the boom, of iding means carried thereby, a frame reelyslidably mounted on the guiding means, a plurality of cutting elementscarried by the frame and comprising endless bucket elevators, and meansfor driving one of the elevators in an opposite direction to the other.

3. In a hole di ging apparatus, the combination with a 00m, and asupport depending from the boom, of guiding means carried by thesupport, a frame freely slidably mounted on the guiding means, cutterelements rotatably mounted about said frame and comprising a pluralityof continuous bucket elevators, and means for driving said elevators inop osite directions continuously independent 0 the position of the samewith relation to the support.

4. In a hole digging apparatus, the combination with a pivoted boom, anda support depending from the boom, of guiding means carried thereby, aframe freely slidably mounted on the guiding means, a plurality ofcutting elements carried by the frame and comprising endless bucketelevators, means for driving one of the elevators in an oppositedirection to the other, and means for receiving and discharging thematerial elevated by said conveyers.

5. In a hole digging apparatus, the combination with a boom and apivoted support depending therefrom, of guiding means carried thereby, aframe slidably mounted on the guiding means, a plurality of cuttingelements carried by the frame and comprising endless bucket elevators,means for driving one of the elevators in an opposite direction to theother, and oppositely arranged chutes for receiving and discharging thematerial from the conveyers in opposite directions.

6. In a hole digging apparatus, a vertically and horizontally movablesupport, guide members pivoted to the support, a frame slidably mountedin the guide members, a plurality of cutter elements rotatably mountedupon the frame and comprising continuous bucket elevators, means tosimultaneously drive the said elevators in opposite directionsindependently of the po sition of the frame on the guide members, andmeans to separate the elevators.

7 In a hole digging apparatus, the combination with a boom pivoted forvertical movement and for horizontal swinging, of guide members pivotedto the boom, al

ground on aging support'carried by the guide mem ers, a frame slidablymounted 1n the guide members, cutter elements rotatably mounted upon theframe and comprising a plurality of endless bucket conveyers a drivingshaft carried by the boom, an

means operated by the driving shaft for continuously and simultaneouslyoperating the conveyers in op osite directions independently of theposition of the frame and the uide members. I

8; n a hole digging apparatus, a verticall and horizontally movablesupport, gui e members pivoted to the support, a

rame slidably mounted in the gui e members, a plurality of cutterelements rotatably mounted upon the frame and comprising continuousucket elevators, means to simultaneously drive the said elevators in oposite directions independently of the position of the frame on theguide members, means to separate the elevators, and means to adjustablyhold the guide members against movement on the boom.

9. In a hole digging apparatus, the combination with a boom pivoted forvertical movement and for horizontal swinging, of guide members pivotedto the boom, a ground engagin support carried by the guide members, arame slidably mounted in the guide members, cutter elements rotatablymounted u on the frame and comprising a pluralitv of endless bucketconveyers, a driving shaft carried by the boom, means operated by thedriving shaft for continuously and simultaneously operating theconveyers in opposite directions independently of the position of theframe and the guide members, a brace connected to the auxiliary support,and means to adjustably connect the opposite end of the brace to theboom.

10. In a hole digging apparatus, the combination with a boom pivoted forvertical movement and for horizontal swinging, of guide members pivotedto the boom, a ground engaging support carried by the guide members, aframe slidably mounted in the guide members, cutter elements rotatablymounted upon the frame and comprising a plurality of endless bucketconveyers, a driving shaft carried by the boom, means operated by thedriving shaft for continuously and simultaneously operating theconveyers in opposite directions independently of the position of theframe and the ide members, and means carried by the fgi zime foradjusting the tension of the conveyers.

11. A hole digging apparatus comprising a plurality of endless cuttingelevators, means to drive one of the elevators in an opposite directionto another of the elevators, and means interposed between the cutters tohold them in separated relation.

throughout their length.

12. In a. hole digging apparatus, the com- In testimon whereof I afiixmy signature bination with a plvoted boom and a supin presence 0 twowitn. port pivoted thereto, of a. frame freely slidably mounted on thesu port, a plurality of EDMUND H 5 cutting elements carrl by the frameand Witnesses:

comprlsing continuous elevators, and means E. EDMONSTON, J r.,

for driving the elevators. M. Fno'rnmomu.

